Highly-accurate and self-adjusting imaging sensor auto-calibration for in-vehicle driver monitoring system or other system

Abstract

A method includes obtaining multiple images of a driver of a vehicle using an imaging sensor associated with the vehicle, where the images of the driver capture the driver's head. The method also includes identifying, in each of at least some of the images, an orientation of the driver's head in the image. The method further includes identifying an average orientation of the driver's head based on at least some of the identified orientations of the driver's head. In addition, the method includes determining whether the driver is inattentive based on the average orientation of the driver's head. Identifying, in each of at least some of the images, the orientation of the driver's head in the image may include identifying a pitch angle and a yaw angle of the driver's head in the image.

What is claimed is: 
     
       1. A method comprising:
 obtaining multiple images of a driver of a vehicle using an imaging sensor associated with the vehicle, the images of the driver capturing the driver's head and obtained in response to the vehicle moving at or above a threshold speed; 
 identifying, in each of at least some of the images, an orientation of the driver's head in the image; 
 identifying an average orientation of the driver's head based on at least some of the identified orientations of the driver's head; 
 identifying a current orientation of the driver's head based on at least one additional image of the driver captured using the imaging sensor; and 
 determining whether the driver is inattentive based on a difference between the current orientation of the driver's head and the average orientation of the driver's head. 
 
     
     
       2. The method of  claim 1 , wherein determining whether the driver is inattentive comprises:
 determining whether the difference between the current orientation of the driver's head and the average orientation of the driver's head exceeds a threshold; and 
 determining that the driver is inattentive when the difference exceeds the threshold. 
 
     
     
       3. The method of  claim 2 , wherein:
 the difference between the current orientation of the driver's head and the average orientation of the driver's head comprises an angular distance; and 
 the threshold comprises a specified angular distance above which is indicative of driver inattentiveness. 
 
     
     
       4. The method of  claim 1 , wherein:
 identifying, in each of at least some of the images, the orientation of the driver's head in the image comprises identifying a pitch angle and a yaw angle of the driver's head in the image; and 
 identifying the average orientation of the driver's head comprises determining an average pitch angle of the driver's head and an average yaw angle of the driver's head. 
 
     
     
       5. The method of  claim 1 , wherein identifying the average orientation of the driver's head comprises:
 identifying a first average orientation of the driver's head based on the identified orientations of the driver's head; and 
 identifying a second average orientation of the driver's head based on the identified orientations of the driver's head that fall within a specified range of the first average orientation. 
 
     
     
       6. The method of  claim 1 , further comprising at least one of:
 identifying another average orientation of the driver's head in response to a position change of the driver within the vehicle; and 
 identifying an average orientation of another driver's head in response to a driver change within the vehicle. 
 
     
     
       7. The method of  claim 1 , further comprising, in response to determining that the driver is inattentive, at least one of:
 triggering an indicator within the vehicle; and 
 collecting information regarding an instance of driver inattentiveness and transmitting the collected information from the vehicle. 
 
     
     
       8. An apparatus comprising:
 at least one processing device configured to:
 obtain multiple images of a driver of a vehicle using an imaging sensor associated with the vehicle, the images of the driver capturing the driver's head and obtained in response to the vehicle moving at or above a threshold speed; 
 identify, in each of at least some of the images, an orientation of the driver's head in the image; 
 identify an average orientation of the driver's head based on at least some of the identified orientations of the driver's head; 
 identify a current orientation of the driver's head based on at least one additional image of the driver captured using the imaging sensor; and 
 determine whether the driver is inattentive based on a difference between the current orientation of the driver's head and the average orientation of the driver's head. 
 
 
     
     
       9. The apparatus of  claim 8 , wherein, to determine whether the driver is inattentive, the at least one processing device is configured to:
 determine whether the difference between the current orientation of the driver's head and the average orientation of the driver's head exceeds a threshold; and 
 determine that the driver is inattentive when the difference exceeds the threshold. 
 
     
     
       10. The apparatus of  claim 9 , wherein:
 the difference between the current orientation of the driver's head and the average orientation of the driver's head comprises an angular distance; and 
 the threshold comprises a specified angular distance above which is indicative of driver inattentiveness. 
 
     
     
       11. The apparatus of  claim 8 , wherein:
 to identify in each of at least some of the images the orientation of the driver's head in the image, the at least one processing device is configured to identify a pitch angle and a yaw angle of the driver's head in the image; and 
 to identify the average orientation of the driver's head, the at least one processing device is configured to determine an average pitch angle of the driver's head and an average yaw angle of the driver's head. 
 
     
     
       12. The apparatus of  claim 8 , wherein, to identify the average orientation of the driver's head, the at least one processing device is configured to:
 identify a first average orientation of the driver's head based on the identified orientations of the driver's head; and 
 identify a second average orientation of the driver's head based on the identified orientations of the driver's head that fall within a specified range of the first average orientation. 
 
     
     
       13. The apparatus of  claim 8 , wherein the at least one processing device is further configured to at least one of:
 identify another average orientation of the driver's head in response to a position change of the driver within the vehicle; and 
 identify an average orientation of another driver's head in response to a driver change within the vehicle. 
 
     
     
       14. The apparatus of  claim 8 , wherein the at least one processing device is further configured, in response to determining that the driver is inattentive, to at least one of:
 trigger an indicator within the vehicle; and 
 collect information regarding an instance of driver inattentiveness and transmit the collected information from the vehicle. 
 
     
     
       15. A non-transitory machine-readable medium containing instructions that when executed cause at least one processor to:
 obtain multiple images of a driver of a vehicle using an imaging sensor associated with the vehicle, the images of the driver capturing the driver's head and obtained in response to the vehicle moving at or above a threshold speed; 
 identify, in each of at least some of the images, an orientation of the driver's head in the image; 
 identify an average orientation of the driver's head based on at least some of the identified orientations of the driver's head; 
 identify a current orientation of the driver's head based on at least one additional image of the driver captured using the imaging sensor; and 
 determine whether the driver is inattentive based on a difference between the current orientation of the driver's head and the average orientation of the driver's head. 
 
     
     
       16. The non-transitory machine-readable medium of  claim 15 , wherein the instructions that when executed cause the at least one processor to determine whether the driver is inattentive comprise:
 instructions that when executed cause the at least one processor to:
 determine whether the difference between the current orientation of the driver's head and the average orientation of the driver's head exceeds a threshold; and 
 determine that the driver is inattentive when the difference exceeds the threshold. 
 
 
     
     
       17. The non-transitory machine-readable medium of  claim 15 , wherein:
 the instructions that when executed cause the at least one processor to identify, in each of at least some of the images, the orientation of the driver's head in the image comprise:
 instructions that when executed cause the at least one processor to identify a pitch angle and a yaw angle of the driver's head in the image; and 
 
 the instructions that when executed cause the at least one processor to identify the average orientation of the driver's head comprise:
 instructions that when executed cause the at least one processor to determine an average pitch angle of the driver's head and an average yaw angle of the driver's head. 
 
 
     
     
       18. The non-transitory machine-readable medium of  claim 15 , wherein the instructions that when executed cause the at least one processor to identify the average orientation of the driver's head comprise:
 instructions that when executed cause the at least one processor to:
 identify a first average orientation of the driver's head based on the identified orientations of the driver's head; and 
 identify a second average orientation of the driver's head based on the identified orientations of the driver's head that fall within a specified range of the first average orientation. 
 
 
     
     
       19. The non-transitory machine-readable medium of  claim 15 , further containing instructions that when executed cause the at least one processor to at least one of:
 identify another average orientation of the driver's head in response to a position change of the driver within the vehicle; and 
 identify an average orientation of another driver's head in response to a driver change within the vehicle. 
 
     
     
       20. The non-transitory machine-readable medium of  claim 15 , further containing instructions that when executed cause the at least one processor, in response to determining that the driver is inattentive, to at least one of:
 trigger an indicator within the vehicle; and 
 collect information regarding an instance of driver inattentiveness and transmit the collected information from the vehicle.